Shaft Structure with Configurable Bending Profile

ABSTRACT

A shaft structure with a configurable bending profile is provided for golf clubs, fishing rods, and the like. The shaft structure employs a plurality of tensioned sections. The golfer, in practice, configures the bending profile of a golf shaft by adjusting the internal pressure of the sections in order to change the stiffness of that section. The combination of sections and their associated stiffness results in an advantageous bending profile. The golfer can, at any time and very easily, change the bending profile of the golf shaft.

FIELD OF THE INVENTION

This invention relates to shafts for golf clubs, fishing rods and the like; and more particularly where the overall bending profile of these devices can be configured by the golfer or user to match physical abilities.

BACKGROUND OF THE INVENTION

Golf shafts and fishing poles are typically manufactured with a predetermined bending profile. The “bending profile” of a golf shaft refers to a distinct flex pattern that a conventional golf shaft exhibits when subjected to a force. The flex pattern is typically measured as the amount of deflection the shaft experiences when the shaft is positioned horizontally and subjected to a constant force. Presently, golf shafts are mass produced with a predefined and fixed bending profile without regard for a golfer's individual swing mechanics. Typically, these parameters are designed in an attempt to accommodate a vast multitude of golfers.

Previous knowledge of golf shaft dynamics resulted in a general understanding that the stiffness of a golf shaft played a role in the performance of a golf club. However, it has been discovered that the overall bending profile of the shaft has much more to do with the performance of a golf club than merely its overall stiffness. The bending profile directly contributes to ball launch angle and spin, both of which can directly affect shot distance and accuracy. Additionally, the bending profile can influence club-head reaction and orientation before the clubface makes contact with the ball.

Prevailing weather conditions can also affect optimum ball flight. For example, on a windy day, a golfer might choose to reconfigure their shaft for a bending profile that promotes a lower penetrating ball flight which reduces the affects of the wind. Conversely, on a day with little or no wind, a golfer may choose to configure the bending profile to promote a higher launch angle.

Various proposals to provide variable stiffness for a golf club shaft (or even a fishing pole) have previously been made that involve using a hollow shaft charged with a gas or liquid fluid that can be pressurized and by mechanical devices such as rods, jackscrews and the like. Increasing the fluid pressure in the shaft increases the shaft stiffness. Increasing the length of the rod increases the tension and hence shaft stiffness.

Such pressurizable shafts are illustrated, for example, by Menzies U.S. Pat. No. 1,831,255, Sears U.S. Pat. No. 2,432,450, Busch U.S. Pat. No. 3,037,775, Burrough U.S. Pat. No. 4,800,668 (a fishing rod), Simmons U.S. Pat. No. 5,316,300, Koch et al. U.S. Pat. No. 5,540,625, Painter U.S. Pat. No. 5,632,693 and Qualizza U.S. Pat. No. 7,226,365.

So far as is known, these variable stiffness, hollow shaft structures of the prior art do not address changing a shaft's bending profile but rather have defined a device which indiscriminately promotes a stiffness change across the entire shaft and never addresses the ability to adjust the bending characteristics of the golf shaft.

SUMMARY OF THE INVENTION

In order for a golf club to be effective and ultimately configured for a golfer by the golfer without requiring the golfer to have intimate knowledge or club-building skills, the present invention provides for a device whose performance characteristics can be easily changed to accommodate the golfer's abilities for any given day any given weather condition and course conditions as well.

The present invention overcomes the inability of prior art shafts to create a unique bending profile. A shaft is provided which can be easily configured to create a variable bending profile that matches the golfer's abilities so as to maximize both shot accuracy and distance.

More particularly, this invention relates to a shaft structure for golf clubs, fishing poles and like apparatus incorporating a variable, configurable bending profile shaft structure. The shaft structure consists of a plurality of sections which may be individually stiffened by virtue of applying a tension force to each individual section. The variable, configurable bending profile shaft does not require special tools or skills to affect the configuring of the bending profile.

By adjusting the tension force in each of the sections and hence the stiffness of each section the golfer is able to accurately “tune” the bending profile of the shaft in order to maximize their skill level.

One object of the present invention is to provide a shaft structure which allows a golfer to change the tension force of individual sections that in-turn changes the stiffness of the section and hence that portion of the golf shaft that is defined by the section.

Another object allows for tuning golf shaft performance by creating a flex profile that results from the cooperation of a multitude of sections under tension. Each section under tension has a unique stiffness that is directly related to the amount of tension applied to a section. Increasing the tension increases the stiffness and reducing the tension reduces the stiffness.

Another object of the present invention is to provide a shaft structure that has a selectable bending profile. Hence, a single assembled shaft structure can replace many different combinations and permutations of golf shafts, golf clubs, and manufacturing procedures and can avoid the need for large inventories of golf clubs with golf club shafts pre-set to different stiffness values, thereby effecting a saving of what would otherwise be an expenditure of substantial amounts of money.

Another object of the present invention is to provide a golf club shaft structure which allows a golfer to customize the bending profile of each shaft of a set of clubs, or of a fishing pole, according to his ability or wishes without being dependent upon the shaft stiffness that happens to result from shaft manufacturing procedures as in the prior art.

Other and further objects, aims, features, advantages, applications, embodiments and the like regarding the present invention will be apparent to those skilled in the art from the present specification, attached drawings, and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which, like reference numerals identify like elements, and in which:

FIG. 1 illustrates a perspective view of one embodiment of a golf club which incorporates a shaft structure of the present invention;

FIG. 2 illustrates a diagrammatical view of the butt section of the shaft structure of FIG. 1;

FIG. 3 illustrates a diagrammatical view of the mid and tip sections of the shaft structure shown in FIG. 1;

FIG. 4 illustrates a detailed view of a piston unit of the butt/mid section of shown in FIG. 2;

FIG. 5 illustrates a detailed view of a piston unit of the mid/tip section of shown in FIG. 3;

FIG. 6 illustrates an alternative embodiment of the piston unit as shown in FIG. 4 and FIG. 5;

FIG. 7 illustrates an alternative embodiment of the present invention which reveals fill valves in lieu of the piston units as shown in FIGS. 2 and 3.

FIG. 8 illustrates an alternative embodiment of the piston unit arrangement as shown in FIG. 4 and FIG. 5;

FIG. 10 reveals another embodiment of the current invention that utilizes tensioning rods in lieu of the piston units as shown in FIGS. 4 and 5.

DETAILED DESCRIPTION

FIG. 1 shows an illustrative golf club 20 that incorporates an embodiment of a shaft structure 21 of the present invention. In the preferred embodiment, shaft structure 21 includes separate, internal sections under tension which may be tensioned to different levels. Three separate, internal, sections 22, 23 and 24 are shown to illustrate the present invention. Fewer or additional separate, internal tensioned sections are within the scope of the present invention. In the preferred embodiment the tensioning of each section 22, 23 and 24 occurs from a fluid being pressurized internally to each section. As well known in the art shaft structure 21 may be made from graphite, ferrous metal such as steel, non-ferrous metal such as aluminum or titanium and the like, plastics, nylons, aramids or any combinations of material.

Tensioned section 22 may be affixed at one end of a conventional club head 30 (not detailed structurally) and tensioned section 24 connects at one end to a circumferentially extending, conventional golf grip 25 (not detailed structurally).

Tensioned section 22 defines a section of the shaft structure 21 which is typically referred to as the tip section; tension section 23 is often referred to as the mid section of the shaft structure 21 and tensioned section 24 is often referred to as the butt section of the shaft structure 21.

In the preferred embodiment and referring to FIG. 2, butt section 24 is defined by a proximal and distal end. The distal end of butt section 24 is further defined by piston unit 26. Proximal end is defined by piston unit 31.

With reference to FIG. 3 the proximal end of the mid section 23 is defined by piston unit 26 and at the distal by piston unit 29. Tip section 22 is defined at the proximal end by piston unit 29 and by bulkhead 68 at the distal end. The distal end of tip section 22 connects to hose 27 of golf club head 30. Those skilled in the art will recognize and appreciate that a plurality of tensioned sections as well as a plurality of tensioning means can be incorporated and that such an arrangement does not deviate from the scope and spirit of the present invention.

With attention toward FIG. 2 therein is shown in detail butt section 24. Conventional golf grip 25 is connected to butt section 24 by a standardized process. The distal end of the butt section 24 is defined by piston unit 26. Additionally, positioned within the proximal end of butt section 24 is piston unit 31 which includes piston 33, piston seal 34, bulkhead 39, jackscrew 43 and stiffness indicator 41. Fluid 37 resides within butt section 24 as defined by piston unit 26 at the distal end and by piston unit 31 at the proximal end. Jackscrew 43 has at one end a hex cap arrangement that allows for the inserting of a hex wrench in order to facilitate the turning of jackscrew 43. The turning of jackscrew 43 in cooperation with the threaded arrangement between jackscrew 43 and bulkhead 39 causes piston 33 to move up and down accordingly. Fluid 37 may be a gas, liquid or other material sufficient to carry the forces as presented by the change in volumes as facilitated by the position of piston 33. Those skilled in the art will recognize that a multitude of other materials may be used as fluid 37 and that using other materials does not deviate from the scope or the intention of the current invention.

Referring to FIG. 4 therein shown in detail is a representation of piston unit 26. In particular, piston unit 26 is comprised of piston 50, piston seal 52, spline 62, wall spline 64, stay collar 58 and stiffness indicator 60. Piston unit 26 serves to define both the butt section 24 above and mid section 23 below. Piston 50, in cooperation with piston seal 52, serves to maintain pressure in both butt section 24 and mid section 23. The representative pressure in butt section 24 as maintained by piston unit 31 at the proximal end and piston unit 26 at the distal end serves to promote an axial tension force upon the butt section 24 of shaft structure 21 that is located between piston 33 of piston unit 31 and piston unit 26. The axial tension force creates a corresponding increase or decrease in stiffness in the butt section 24 of the shaft structure 21. The stiffness of butt section 24 is indicated by stiffness indicator 41 as viewed through window 12 directly affixed to and made part of shaft structure 21 (FIG. 1). When a desired stiffness is achieved piston unit 26 is locked in place by the cooperative engaging of spline 62 with wall spline 64. In free-movement spline 62 of piston unit 26 is not engaged with wall spline 64 and therefore is free to traverse up or down. The location of piston unit 26 serves to increase/decrease the volume of mid section 23 while simultaneously decreasing/increasing the volume of butt section 24 and hence a corresponding increase/decrease in pressure of the respective sections 23 and 24. When a desired pressure is reached within mid section 23 as defined by the position of piston unit 26, stay collar 58 adjusting hex screw 54 is turned in order to decrease the circumference of stay collar 58. This in turn slightly reduces the diameter of shaft structure 21 which then prompts spline 62 to cooperatively engage with wall spline 64. The wall of the shaft structure 21 adjacent to stay collar 58 is sufficiently thin enough so as to allow the reduction of the diameter of stay collar 58 to effect the engagement of spline 62 with wall spline 64. The combination of stay collar 58 and the wall of shaft structure 21 at the point of contact provides for structural integrity. In this manner piston unit 26 is effectively locked in place. With piston unit 26 locked in place a pressure is developed within butt section 24 as defined by the position of piston 30. In this manner a unique, independently stressed butt section 24 of shaft structure 21 occurs.

Referring to FIG. 5 therein is shown in further detail a representation of piston unit 29. In particular, piston unit 29 is comprised of piston 70, piston seal 72, spline 82, wall spline 84, stay collar 78 and stiffness indicator 80. Piston unit 29 serves to define both the mid section 23 above and tip section 22 below piston unit 29. Piston 60, in cooperation with piston seal 62, serves to maintain pressure in both mid section 23 and tip section 22. The representative pressure in mid section 23 as maintained by piston unit 26 at the proximal end and piston unit 29 at the distal end serves to promote an axial tension force upon the section of the shaft 21 that is located between piston unit 26 and piston unit 29. The axial tension force creates a corresponding increase or decrease in stiffness in the mid section 23 of shaft structure 21. The stiffness of mid section 23 is indicated by stiffness indicator 80 as viewed through window 10 which is affixed to and made part of shaft structure 21 (FIG. 1). Piston unit 29 is locked in place by the cooperation of spline 82 with wall spline 84. In free-movement spline 82 of piston unit 29 is not engaged with wall spline 84 and therefore is free to move. When a desired pressure is reached which is, in part, defined by the position of piston unit 29 stay collar 78 hex adjusting screw 74 is turned in order to decrease the circumference of stay collar 78. This in turn reduces the diameter of shaft structure 21 at that point which then causes spline 82 to cooperatively engage wall spline 84. The combination of stay collar 78 and the wall of shaft structure 21 at the point of contact provides for structural integrity. In this manner piston unit 29 is effectively locked in place. With piston units 26 and 29 locked in place and with the corresponding loads carried by the piston units 26 and 29 a unique tension exists within the mid section 23 of shaft structure 21 as defined by piston units 26 and 29. The unique tension exhibits an axially tension force within this section and a corresponding stiffness results within the mid section 23 of shaft structure 21.

With reference to FIG. 3 tip section 22 is defined by piston unit 29 at the proximal end and by bulkhead 68 at the distal end. Piston unit 29, in cooperation with bulkhead 68, serves to maintain pressure in tip section 22. The representative pressure in tip section 22 as maintained by piston unit 29 at the proximal end and bulkhead 68 at the distal end serves to promote an axial tension force upon the tip section of shaft structure 21 that is located between piston unit 29 and bulkhead 68. The axial tension force creates a corresponding increase or decrease in stiffness in the section of the shaft structure 21. The stiffness of the tip section 22 is indicated by stiffness indicator 80 as viewed through window 8 (FIG. 1).

Configuring a unique bending profile is defined by the pressure in each individual section 22, 23 and 24 which in-turn creates a unique axial tension force in each section 22, 23 and 24 which further promotes a stiffness in each section 22, 23 and 24 that is unique to that section. Piston units 26 and 29 are sufficiently small enough and strategically placed so as to accurately control the position and length of the individual sections 22, 23 and 24. Those skilled in the art will recognize that a plurality of sections may be incorporated into the present invention as well as further means to ideally locate and define each section and that doing so does not deviate from the scope or the spirit of the present invention.

As an alternative, a spline section similar in design to spline sections 64 and 84 may run the entire length of shaft structure 21. In this manner sections 22, 23 and 24 can be defined to be a large or as small as the golfer may favor. Additionally, those skilled in the art will recognize that a multitude of locking device may be discovered to lock both piston units 26 and 29. As well piston unit 31 may be served by a multitude of different devices and that such devices does not deviate from the scope nor the spirit of the current invention.

In practice and when a golfer chooses to adjust the bending profile the golfer will first loosen stay collars 58 and 78 for piston units 26 and 29 respectively. The golfer then turns jackscrew 43 via a hex wrench. Clockwise movement of jackscrew 43 causes piston 33 of piston unit 31 to move downward (with reference to FIG. 2). Counter-clockwise movement of jackscrew 43 causes piston 33 of piston unit 31 to move upward (with reference to FIG. 2). A downward movement of piston 33 compresses fluid 37. Compression of fluid 37 exerts a force upon piston unit 26 causing piston unit 26 to move downward. Movement of piston unit 26 compresses fluid 35 (FIG. 3). Compression of fluid 35 promotes a force upon piston unit 29 causing piston unit 29 to move downward. Movement of piston unit 29 compresses fluid 31. Continued clockwise turning of jackscrew 43 continues the process until the desired stiffness is reached in tip section 22 as indicated by stiffness indicator 80 as viewed through window 8 located on shaft structure 21. At this time the golfer tightens stay collar 78 which effectively locks piston unit 29 in place. In this manner pressure in tip section 22 is maintained as well as isolating and segregating it from mid section 23 and butt section 24.

After configuring the stiffness in tip section 22 the golfer then adjusts the stiffness in mid section 23 by either turning jackscrew 43 clockwise to increase the pressure in mid section 23 or counter-clockwise to decrease the pressure. If an increase in stiffness for mid section 23 is required turning jackscrew clockwise further compresses fluid 37 which then exerts further pressure on piston unit 26 causing it to move downward. Further downward movement of piston unit 26 compresses fluid 35. Since piston unit 29 is now locked in position pressure builds within mid section 23. If a decrease in stiffness for mid section 23 is required turning jackscrew counter-clockwise will decompress fluid 37 which then reduces pressure on piston unit 26 causing it to move upward. Upward movement of piston unit 26 increases the volume within mid section 23 and therefore reduces the pressure which necessarily reduces the axial force and, hence, the stiffness. Movement of piston unit 26 continues until the required stiffness is achieved as indicated by stiffness indicator 60 and as viewed through window 10 located in shaft structure 21. At this time stay collar 58 is tightened thereby restricting further movement of piston unit 26. Therefore, a unique mid section 23 is defined by locked piston unit 26 and 29. Mid section 23 then experiences a unique and isolated pressure. The unique pressure facilitates a unique stiffness within mid section 23.

Further turning of jackscrew 42 facilitates the final adjustment of butt section 24. Turning jackscrew 43 clockwise serves to compress fluid 37 while turning jackscrew counter-clockwise serves to decompress fluid 37. Since piston unit 26 is now locked in place pressure in butt section 24 will proportionately increase/decrease which serves to change the axially force upon the butt section 24 of shaft 21 which is defined at the proximal end by piston unit 31 and at the distal end by piston unit 26. Stiffness indication of the butt section is indicated by indicator 41 as viewed through window 12 of shaft structure 21.

Given the ability to configure the stiffness of individual shaft 21 sections, a substantial bending profile can be obtained. For instance, if one were to desire a mid kick-point shaft structure 21with a “soft tip” tip section 22 will require a pressure less than butt section 24. However, because of the need for a mid kick tip section 22 pressure would be greater than mid section 23. In this configuration stiffness indicators would reveal, as an example, 9, 5, 6 for sections 24, 23 and 22 respectively. Conversely, if one requires a low kick-point tip section 22 pressure would be less than both mid section 23 and butt section 24 pressure. Requiring a high kick-point would necessarily dictate pressure in tip section 22 and mid section 23 be greater than pressure in butt section 24.

FIG. 6 reveals another embodiment of locking piston units 26 and 29. In this embodiment locking pawls 93 and 99 cooperates with detents 96 and 98 respectively when the piston unit 100 is locked into place. When the piston unit 100 is chosen to move magnetic collar 94 is placed over the shaft 21 in the appropriate position so as to cause pawl 93 and 99 to retract against springs 95 and 91 by virtue of the magnetic force between magnetic collar 94 and locking pawls 93 and 99. With the retraction of locking pawls 93 and 99 piston unit 100 is allowed to move freely to another position so as to allow a greater or lesser pressure and hence a greater or lesser stiffness. When the appropriate stiffness is achieved magnetic collar 94 is removed causing pawls 93 and 99 to extend by virtue of the force imparted by springs 91 and 95 upon locking pawls 93 and 99. Thus locking pawls 93 and 99 engage detents 96 and 98 respectively.

FIG. 7 reveals an alternative embodiment wherein sections 24, 23 and 22 are fitted with micro-miniature valves 101, 104 and 108 respectively. Pressurized fluids 37, 35 and 31 would be introduced into the accompanying sections 24, 23 and 22 by virtue of miniaturized valves 101, 104 and 108. In this manner pressurization units 26, 29 and 31 would be eliminated.

FIG. 8 reveals yet another embodiment where each section has as an associated pressurization unit that is adjacent to and contiguous with the associated section. As an example and as shown, mid section 123 would be pressurized by piston 191 and seal 196. Facilitating the movement up or down of piston 191 occurs through a longitudinal transaction as facilitated by jackscrew 192 in threaded cooperation with bulkhead 189. The golfer would facilitate the turning of jackscrew 192 via hex detail 87 through slot 193 strategically placed in shaft structure 21.

FIG. 10 reveals another embodiment where tensioning of the sections 22, 23 and 24 occurs from an adjustable mechanical means located internal to each section 22, 23 and 24. One such mechanical means could be an adjustable length rod 224. The adjustable length rod 224 would serve to create a force on opposite ends of the adjustable length rod 224 which would transfer the force to the ends of section 23 by virtue of bulkheads 227 and 229. In this manner the adjustable length rod 224 would serve to create a tension within the section 23. The golfer adjusts the tension within each section by adjusting the length of the adjustable length rod 224 via hex arrangement 226. Turning hex arrangement 226 causes the threaded arrangement 223 to turn as well causing adjustable rod 224 to expand or contract. Facilitation of turning hex arrangement 226 is via slot 225 in shaft structure 21. Adjusting the adjustable length rod 224 to be longer increases the tension within a section and adjusting the adjustable length rod 224 to be shorter decreases the tension within a section.

Although in the preferred embodiment three tensioned sections are shown those skilled in the art will readily recognize and appreciate that a plurality of tensioned sections can be used and in doing so does not deviate from the scope and the spirit of the present invention. 

1. A configurable bending shaft structure comprising a plurality of sections including a first section having a first stiffness and a second section having a second stiffness.
 2. The shaft structure as in claim 1 wherein said first and second sections are tensioned by a tensioning apparatus.
 3. The shaft structure as in claim 2 wherein said tension serves to stiffen said first and second sections.
 4. The shaft structure as in claim 2 wherein said tensioning apparatus is comprised of a compressed fluid.
 5. A shaft structure as in claim 4, wherein said compressed fluid is pressurized by a first pressurizing apparatus to adjust said tension.
 6. A shaft structure as in claim 5, wherein said first pressurizing apparatus includes a first piston.
 7. A shaft structure as in claim 5, wherein said pressurizing apparatus includes a first biasing apparatus to adjust said pressure of said compressed fluid.
 8. A shaft structure as in claim 5, wherein the shaft structure includes a second pressurizing apparatus having a second piston.
 9. A shaft structure as in claim 8, wherein said second pressurizing apparatus includes a second biasing apparatus to adjust a second pressure.
 10. A shaft structure as in claim 1, wherein the shaft structure is connected to a golf club.
 11. A shaft structure as in claim 1, wherein the shaft structure connected to a fishing rod.
 12. A method for configuring a configurable bending shaft structure, comprising the steps of: setting the first stiffness of a first section; setting the second stiffness of a second section;
 13. A method for configuring a configurable bending shaft structure as in claim 12 wherein said first section and said second section is a fluid-filled chamber.
 14. A method for configuring a configurable bending shaft structure as in claim 13, wherein the method includes the step of adjusting said first stiffness of said first section by changing a first pressure by a first apparatus.
 15. A method for configuring a configurable bending shaft structure as in claim 13, wherein the method includes the step of adjusting said second stiffness of said second section by changing a second pressure by a second apparatus.
 16. A method for configuring a configurable bending shaft structure as in claim 14, wherein said first apparatus includes a first piston.
 17. A method for configuring a configurable bending shaft structure as in claim 14, wherein said first apparatus includes a first biasing apparatus to adjust said first pressure.
 18. A method for configuring a configurable bending shaft structure as in claim 15, wherein said second apparatus includes a second piston.
 19. A method for configuring a configurable bending shaft structure as in claim 15, wherein said second apparatus includes a second biasing apparatus to adjust said second pressure. 